Background: Incompetence of the anterior cruciate ligament (ACL) confers knee laxity in the sagittal and axial planes that is measurable with clinical examination and diagnostic imaging. Hypothesis: An ACL-deficient knee will produce a more vertical orientation of the lateral collateral ligament (LCL), allowing for the entire length of the LCL to be visualized on a single coronal slice (coronal LCL sign) on magnetic resonance imaging. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Charts were retrospectively reviewed from April 2009 to December 2017 for all patients treated with ACL reconstruction (constituting the ACL-deficient cohort). A control cohort was separately identified consisting of patients with a normal ACL and no pathology involving the collateral ligaments or posterior cruciate ligament. Patients were excluded for follow-up <2 years, incomplete imaging, and age >19 years. Tibial translation and femorotibial rotation were measured on magnetic resonance images, and posterior tibial slope was measured on a lateral radiograph of the knee. Imaging was reviewed for the presence of the coronal LCL sign. Results: The 153 patients included in the ACL-deficient cohort had significantly greater displacement than the 70 control patients regarding anterior translation (5.8 vs 0.3 mm, respectively; P < .001) and internal rotation (5.2° vs −2.4°, P < .001). Posterior tibial slope was not significantly different. The coronal LCL sign was present in a greater percentage of ACL-deficient knees than intact ACL controls (68.6% vs 18.6%, P < .001). The presence of the coronal LCL sign was associated with greater anterior tibial translation (7.2 vs 0.2 mm, P < .001) and internal tibial rotation (7.5° vs –2.4°, P = .074) but not posterior tibial slope (7.9° vs 7.9°, P = .973) as compared with its absence. Multivariate analysis revealed that the coronal LCL sign was significantly associated with an ACL tear (odds ratio, 12.8; P < .001). Conclusion: Our study provides further evidence that there is significantly more anterior translation and internal rotation of the tibia in the ACL-deficient knee and proves our hypothesis that the coronal LCL sign correlates with the presence of an ACL tear. This coronal LCL sign may be of utility for identifying ACL tears and anticipating the extent of axial and sagittal deformity.

Objectives: This study highlights demographics and orthopaedic injuries of electric scooter–related trauma that presented to our institution over a 27-month period. Design: Retrospective review. Setting: Urban Level 1 trauma center. Patients: Patients presenting to the emergency department, trauma bay, or outpatient clinic after electric scooter injury were identified from November 2017 through January 2020 using ICD-10 diagnosis codes. Main Outcomes: Patient charts were reviewed for demographics, injury characteristics, imaging, treatment, perioperative data, and Injury Severity Scores. Results: Four hundred eighty-five patients presented during the study period. Of these, 44% had orthopaedic injuries, including 30% with pelvis or extremity fractures. There were 21 (10%) polytraumatized patients in the orthopaedic cohort. The age ranged from 16 to 79 years (average 36 years), with 58% men, and 18% were visitors from out of town. Of 49 patients requiring orthopaedic surgery, 8 underwent surgery on an urgent basis. The average Injury Severity Score for orthopaedic patients was 8.4 with a median of 5.0 for nonoperative injuries versus a significantly higher median of 16.0 for operative injuries. Twenty-nine percent of patients were intoxicated and only 2% wore a helmet. Conclusions: Electric scooter injuries are increasing, and many patients sustain high-energy injuries. As electric scooter use continues to increase, the prevalence of orthopaedic injuries is also likely to rise. Further studies are needed to fully understand the impact scooter-related injuries have on individual patients and the health care system. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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